Small-Scale Fisheries Bycatch Jeopardizes Endangered Pacific Loggerhead Turtles

Abstract

Background. Although bycatch of industrial-scale fisheries can cause declines in migratory megafauna including seabirds, marine mammals, and sea turtles, the impacts of small-scale fisheries have been largely overlooked. Small-scale fisheries occur in coastal waters worldwide, employing over 99% of the world's 51 million fishers. New telemetry data reveal that migratory megafauna frequent coastal habitats well within the range of small-scale fisheries, potentially producing high bycatch. These fisheries occur primarily in developing nations, and their documentation and management are limited or non-existent, precluding evaluation of their impacts on non-target megafauna. Principal Findings/Methodology. 30 North Pacific loggerhead turtles that we satellite-tracked from 1996-2005 ranged oceanwide, but juveniles spent 70% of their time at a high use area coincident with small-scale fisheries in Baja California Sur, Mexico (BCS). We assessed loggerhead bycatch mortality in this area by partnering with local fishers to 1) observe two small-scale fleets that operated closest to the high use area and 2) through shoreline surveys for discarded carcasses. Minimum annual bycatch mortality in just these two fleets at the high use area exceeded 1000 loggerheads year 21 , rivaling that of oceanwide industrial-scale fisheries, and threatening the persistence of this critically endangered population. As a result of fisher participation in this study and a bycatch awareness campaign, a consortium of local fishers and other citizens are working to eliminate their bycatch and to establish a national loggerhead refuge. Conclusions/Significance.. Because of the overlap of ubiquitous small-scale fisheries with newly documented highuse areas in coastal waters worldwide, our case study suggests that small-scale fisheries may be among the greatest current threats to non-target megafauna. Future research is urgently needed to quantify small-scale fisheries bycatch worldwide. Localizing coastal high use areas and mitigating bycatch in partnership with small-scale fishers may provide a crucial solution toward ensuring the persistence of vulnerable megafauna.

O Santuário Ecológico de Ilhabela como área marinha protegida a ser incorporada ao SNUC: panorama atual e próximos passos

“…Segundo Hall (2001), se mal planejadas, atividades turísticas podem gerar danos a ambientes naturais. Os dados levantados por Sá (2016) indicam que na área do SEI há distintas atividades, associadas principalmente ao turismo, que podem causar danos aos organismos marinhos, como, por exemplo, o trânsito de embarcações, que ameaça, entre outros animais, tartarugas marinhas e cetáceos que utilizam o Canal como área de passagem; fundeio em áreas indevidas (Milazzo et al, 2004); pisoteio e contato com animais marinhos, que prejudica organismos como corais, invertebrados e algas (Roman et al, 2007;Worachananant et al, 2008;Di Franco et al, 2009;Giglio et al, 2016); coleta de espéci-mes, que pode causar desequilíbrio das populações das espécies coletadas além de menores taxas de crescimento e de sucesso reprodutivo (Davenport & Davenport, 2006;Lucas & Smith, 2016); alimentação de animais, que pode causar dependência dessa alimentação suplementar, desenvolvimento de comportamento agressivo, competitividade entre espécies e habituação à presença humana (Milazzo et al, 2006;Milazzo, 2011;Dubois & Fraser, 2013); pesca amadora e por meio de redes, podendo causar captura incidental (Peckham et al, 2007;Wallace et al, 2013); pesca predatória, com a utilização de arpão, entre outros.…”

The leatherback turtle Dermochelys coriacea (Vandelli, 1761) in the bay of Biscay and the North East Atlantic

“…Bycatch during fishing manoeuvres (DUGUY et al, 1998;LEWISON et al, 2004aLEWISON et al, , 2004bLEWISON & CROWDER, 2007;PECKHAM et al, 2007;BÁEZ et al, 2007 and2008;WA-LLACE et al, 2008), climate change (POLOCZANSKA et al, 2009), the loss of habitat both in egg-laying areas and on the open sea (LUTZ & MUSICK, 1997;BOLTEN & WITHERINGTON, 2003) and sea pollution due to heavy metals and solid residues (DUGUY et al, 1998;MROSOVSKY et al, 2009) are factors responsible for the decline in populations worldwide.…”

“…Artisanal fisheries would seem as a whole to be responsible for bycatch on a major scale. This decreases the effectiveness of the means for reducing bycatch which is being put into practice by industrial fisheries worldwide (PECKHAM et al, 2007;ALFARO-SHIGUETO et al, 2008;ALFARO-SHIGUETO et al, 2010). Proposals to reduce bycatch would benefit from studies quantifying the bycatch by small-scale fisheries and the impact on habitat of endangered species (SOYCAN et al, 2008).…”

Biologging technologies: new tools for conservation. Introduction

“…In addition to providing critical information on the movements and behaviors of a variety of animals, biologging data are increasingly being applied to management and conservation policy (Peckham et al 2007, Burger & Shaffer 2008, Shillinger et al 2008, Witt et al 2008, Greene et al 2009). The use of biologging tools for the conservation of threatened and endangered species was, in fact, a principal theme of the symposium.…”